Related papers: Overview on low mass scalars at $e^+e^-$ facilitie…
We combine searches for scalar resonances at the electroweak scale performed by the Large Hadron Collider experiments ATLAS and CMS where persisted excesses have been observed in recent years. Using both the side-bands of Standard Model…
We summarize the potential of high--energy $\ee$ linear colliders for discovering, and in case of discovery, for studying the signals of extended gauge models. We will mainly focus on the virtual signals of new neutral gauge bosons and on…
Motivations for physics beyond the Standard Model are reviewed, with particular emphasis on supersymmetry at the TeV scale. Constraints on the minimal supersymmetric extension of the Standard Model with universal soft supersymmetry-breaking…
We discuss the physics motivations for building a 500 - 1 TeV electron-positron linear collider. The state of the art collider technologies and the physics-driven machine parameters are discussed. A survey of some of the phenomena well…
From a theoretical point of view it is not hard to imagine gaugino masses being much lighter than scalar masses. The dominant contributions to gaugino masses are then their anomaly-mediated values. Given current lower bounds on gauginos,…
I summarize the prospects for discovering and studying the properties of Higgs particles at future high-energy and high-luminosity $e^+e^-$ linear colliders. I will focus on the Higgs particle of the Standard Model and the Higgs bosons…
Scalar fields with inverse power-law effective potentials may provide a negative pressure component to the energy density of the universe today, as required by cosmological observations. In order to be cosmologically relevant today, the…
Gravity theories with non-minimally coupled scalar fields are used as characteristic examples in order to demonstrate the challenges, pitfalls and future perspectives of considering alternatives to general relativity. These lecture notes…
The lack of evidence for new physics beyond the standard model at the LHC points to a paucity of new particles near the weak scale. This suggests that the weak scale is tuned and that supersymmetry, if present at all, is realized at higher…
The Large Electron Positron collider observed an indication for a new Higgs boson with a mass around $95$\,GeV-$100$\,GeV in the process $e^+e^-\to Z^*\to ZS$ with $S\to b\bar b$. The interest in this excess re-emerged with the di-photon…
We examine some of the theoretical and phenomenological implications of the Higgs boson discovery and discuss what these imply for future Higgs studies at the LHC and future colliders. In particular, one of the outstanding unanswered…
We present a search for new scalar bosons predicted by the Inert Doublet Model at an $e^+e^-$ machine with centre-of-mass energies of 240 and 365 GeV. Within this model, four additional scalar bosons ($H,\, A,\, H^+$ and $H^-$) are…
We analyze the manifestations of new matter particles predicted by models of new physics beyond the Standard Model, at present and future high--energy colliders. We consider both the production of these new particles and some of their…
The single production of leptoquarks in $e^+e^-$, $e\gamma$ and $\gamma \gamma$ linear colliders is discussed. We show that these new particles could be seen in such machines even if their mass is close to the kinematic limit. (Invited talk…
Recent theories propose that quantum gravity effects may be observable at LEP energies via gravitons that couple to Standard Model particles and propagate into extra spatial dimensions. The associated production of a graviton and a photon…
The search reaches for both scalar($S$) and vector($V$) leptoquarks at future hadron colliders are summarized. In particular we evaluate the production cross sections of both leptoquark types at TeV33 and LHC as well as the proposed 60 and…
Littlest Higgs model predicts some extra particles beyond the Standard Model. Among them, an extra neutral gauge boson A_H is lightest and its mass could be a few hundred GeV. We study production and decay of A_H at future e^+ e^- inear…
We investigate the bounds on light pseudoscalars that arise from a variety of collider searches. Special attention is thereby devoted to the mass regions $[3, 5] \, {\rm GeV}$ and $[9,11] \, {\rm GeV}$, in which a meaningful theoretical…
Over the past two decades, the high energy physics community has been actively discussing and developing a number of post-LHC collider projects; however, none of them have been approved due to high costs and the uncertainty in post-LHC…
Tackling the many open questions in particle physics will require the construction of new colliders. This short note includes a few considerations that seem to be brought up rarely.